Piston ring



Dec. 8, 1931. J BULLARD 1,835,139

PISTON RING Filed Oct. 27, 1928 F Hllln.

I N V EN TOR.

A TTORNE Y.

Patented Dee, 193E EARL d. BULLARD, 01E BURLINGAME, GALHOENIA JPISTQNRING Application filed October 27, 1928. Serial No. 315,4:02.

The present invention relates to improvements in piston rings designedprimarily for use in internal combustion motors to maintain an efiectiveseal between the cylinder wall and piston while the latter is operatingin the cylinder under pressure.

@ne of the principal objects of the invention is to provide a ringconsisting of arcuate sections arranged that they form a circular bodywith the sections interlocking at corresponding ends, there beingprovided pressure means in rear of the sections to provide an equalpressure on the surface of the com pleted ring.

A further object is to provide a sectional ring consisting ofsuperimposed series of ar- 'euate plates arranged with the ends of theplates of the respective series in relative stag-' gered interfittingrelation.

A further object is to provide a fulcrum connection between certain ofthe plates of the superimposed series, the fulcrum connections affordingguides for controlling the radial movement of the plates in their piston5 receiving slot and precluding circumferential movement of the plateswithin the slot.

A further object is to provide a spring means for acting on the inneredges of the arcuate plates to force the outeredges thereof into uniformfrictional contact with the cylinder wall.

Another object is to groove or channel the outenedge of the plates toenable the same to rapidly seat and seal against the cylinder Wall ontheir initial installation.

With the above mentioned and other objects in view, the inventionconsists in the novel construction and combination of parts hereinafterdescribed, illustrated in the accompanying drawings and pointed out inthe claims hereto appended: it being understood that various changes inthe form, proportion, size and minor details of construction-w-withr inthe. scope of the claims may be resorted to without departing from thespirit or sacrificing any of the advantages of the invention.

In the drawings Figure 1 is a view in vertical section of the preferredembodiment of my invention as applied to a reciprocating piston.

Figure 2 is a transverse section on line 22 of Fig. 1, viewed in thedirection of the arrow.

Figure 3 is a View in plan of one of the areuate plates.

Figure 4 is a transverse sectional view through the fulcrum point of twoplates arranged in superimposed relation.

In the drawings, wherein like characters of reference designatecorresponding parts,1 indicates a suitable cylinder within which isreciprocably mounted a piston 2, having a WIiSt pin 3, of theconventional type.

The piston 2 is circumferentially grooved at a, the groove beingillustrated as rather narrow in width, but of considerable depth. Theupper Wall surface of the groove 4, at suitable points, is inwardlyslotted at 5, affording radial guides.

The ring in the present embodiment COIIlprises a plurality of areuateplates 6, each longitudinally grooved on its outer edge at 7. Each plateat its opposite ends is provided with a tongue 8. Each tongue 8 is of aWidth less than that of the plate 6 and the tongues are located one oneach side of a line disposed longitudinally of the plate 6, theirreversed positioning being clearly illustrated in Fig.3.

When in use and a single series of plates 6 is employed, the same arepositioned with in the groove 4 in circular formation with the tongues 8at adjacent ends of successive plates projecting beyond each other, withthe plates in a common plane. Thus, a broken or interlockin joint isprovided between adjacent ends of successive plates of the ring withcorresponding ends of successive plates hearing on the inner edge ofeach other.

In this single embodiment installation, a fulcrum pin 9 projecting intothe slot 5 affords a means for radially guiding the respective platesand precludes the longitudinal movement of the plates within the groove4.

Suitable elongated bar. springs 10 positioned preferably one between theinner edge 11 of the respective plates 6 and the inner edge 12 of thegroove 4, with the center r the spring bearing on the edge 12 at a pointin radial alignment with the pin 9 of its respective plate and with itsopposite ends bearing on the inner edges of adjacent plates, serve toforce the outer edges of the plates into frictional contact with theinner wall surface of the cylinder 1, and exert a uniform pressure onthe respective plates.

While I have preferably described the in- I stallation of a singlelayerof plates, the preferred installation is as illustrated, consistingof plates arranged in groups, and the plates of each group insuperimposed relation.

Thus, there is provided superimposed rings of duplicate construction,arranged with the ends of the plates of the adjacent rings in staggeredrelation.

In the preferred embodiment, the superimposed plates 6 of each group aredisposed in partial overlapping relation with a in 9 affording a fulcrumconnection there etween, and with the projecting portion of the pinoperating within one of the slots 5. In this type of installation, eachspring 10 effectively acts on four plates exerting uniform outwardpressure thereon to u niformally expand the ring structure' I claim2- 1. The combination with a cylinder and a piston therefor having aring groove, one wall of which is radially slotted, of a piston ring insaid groove comprising a plurality of duplicate plates arcuate in plan,arranged in superimposed series with the ends of the plates of a givenseries overlapping, fulcrum pins passing transversely through certainplates of the respective series to provide fulcrum points therebetween,the ends of said pins projecting beyond the faces of plates of the sameseries for receptionin said radial slots of the ring groove to precludecircumferential movement of the ring in the groove, and spring meanswithin the base of the ring groove to hold said plates outwardlyagainst, the cylinder wall.

2. A piston ring mountable in a ring groove of a piston, comprising aplural series of rings arranged in superimposed relation, 1 each ringconsisting of a plurality of arcuate plates longitudinally recessed attheir ends and arranged in end to end circle forming relation, with aportion of the adjacent ends of adjacent plates extending into therecess of the next adjacent plate forming a slidable arcuate joint thefaces of which are concentric with the outer face of the plates, theplates of the respective series being arranged in relative overlyingrelation to present the joints in staggered relation, and a fulcrum pinpassing transversely through overlying plates of the respective ringsnear their overlying ends to provide fulcrum points therebetween andafford a single point of fulcrum for each plate, and a bowed leaf springmeans associated with said ring forming plates so as to haveinterterminal bearing against the inner wall of the ring groove andhaving each of its opposite ends bearing against separate adjacentsegments of the ring forming plates.

3. A piston ring structure comprising superimposed rings each'consistingof a plurality of segmental plates having their opposite endslongitudinally recessed from opposite edges of the plate and providinglongitudinally extending tongues whose side edge walls are concentricwith the outer edge wall of the plate, said plates disposed in suerimposed layers, the plates of each lay r arranged in end to end circleforming relation with the tongues of adjacent ends of adjacent plates ofeach'layer' slidably engaging each other affording an interlockingjoint, the joints of the plates of the respective layers being arrangedin vertically staggered relation, and a connection between overlyingplates of the respective layers affording relative pivotal movement, andleaf spring means associated with said ring forming plates, said springmeans bearing centrally against the inner wall of the ring groove andhaving each of its opposite ends bearing against a separate segment ofthe ring forming plates.

In testimony whereof I have signed my name to this specification.

EARL J. BULLARD.

